1. Field of the Invention
The present invention relates to sensors for detecting chemicals and in particular to a sensor for detecting and distinguishing atomic hydrogen or atomic deuterium oxygen, carbon monoxide, and nitric oxide.
2. Description of the Prior Art
Electron transport through a metal-semiconductor interface is determined largely by the Schottky barrier between them.
The detailed pathways of energy transfer in exothermic and endothermic reactions at a metal surface is incompletely understood and of fundamental interest. Bond formation energy of up to several electron volts is transferred into the substrate during such exothermic reactions. Since bulk phonon energies are typically two orders of magnitude smaller, it has been appreciated by the prior art that non-adiabatic excitations of electron-hole pairs may be an alternative to the creation of multiple phonons as a mechanism for sensor detectors. With surface reactions at thermal collision energies, there are few examples of energy transferring to the electronic system accompanied by light emission or chemiluminescence and exoelectron ejection. Chemiluminescence and exoelectron injection are observed only with exothermic adsorption of electronegative molecules on reactive metal surfaces. In addition, exoelectron emission requires that the metal have a low work function. Heretofore, there has been no direct experimental evidence for adsorption induced electron-hole pair excitations at transition metal surfaces.
Therefore, what is needed is some type of sensor design or principal in which adsorption induced electron hole pair excitations at a transition metal surface can be exploited to provide a chemical sensor.